This NFL season has produced several surprises, as always. Who knew that the Chiefs defense was so dominant? That having coach Sean Payton back would have such a profound impact on the Saints? That the Falcons would fall apart so quickly?

And perhaps most bizarre, a few miles south on I-95: What the heck has happened to Eli Manning?

The Giants quarterback, now in his 10th season, hardly resembles the quarterback who twice slayed the Patriots in the final minute of the Super Bowl to win MVP both times. Manning is having one of the worst seasons of any quarterback this year, and is on pace for the worst year of his career.

Manning’s 16 interceptions are the most in the NFL and put him on pace for 28, which would surpass his career high of 25.

Manning has never been the most accurate passer, with a career completion percentage of 58.4, but he’s at just 55.6 percent this year, which would be his lowest mark since 2005, his first full year as the starter.

Manning is 30th in completion percentage, 31st in passer rating (68.5, also a career low), and has committed a league-high five intentional grounding penalties (no other quarterback has more than two).

The Giants’ 28 turnovers are by far the most in the league — Arizona is next at 21.

Manning’s poor play has directly affected the Giants’ record.

They began the season 0-6 as Manning threw 15 interceptions, and even on their current three-game winning streak, Manning is averaging just 195 yards passing per game.

As good as Peyton Manning has been in leading the league’s top aerial show in Denver, Eli has been that bad in New York.

It got so bad last month that Giants coach Tom Coughlin was actually asked about benching Manning, which seemed inconceivable before the season.

“What I see with Eli Manning is inexplicable at this point in his career,” ESPN’s Ron Jaworski said last week. “Decision-making, erratic throwing, bad mechanics, sloppy at times.

“I can’t explain it. This guy has far too much talent, he’s been in the system, he knows what to do with the football. He’s just been off this season.”

Coughlin has tried to deflect the blame for the Giants’ slow start away from Manning.

“I can understand what the football world may think. Actually, what should happen is people should shift [blame] to me,’’ Coughlin said.

“In this one, criticizing the quarterback for the outcome for everything there at the end of the game is not right . . . I’m sure he would tell you that he would like to play better, there’s no doubt about that. I have every confidence in the world that he will.”

Certainly, the cast around Manning hasn’t helped. A multitude of injuries at offensive line and running back have put the running game in shambles, with the Giants ranked 29th in the league at 76.9 yards per game and 30th at 3.2 yards per carry.

And a tough early schedule didn’t help, either. The Giants opened the season against the Cowboys, Broncos, Panthers, Chiefs, Eagles, and Bears.

Former league MVP
Rich Gannon sees in Manning a quarterback who is trying to do way too much to compensate for the failings of his teammates.

“I think what’s happened to him is what happens to other QBs, and I experienced it — when things aren’t going well around you, you start saying, ‘If I don’t do it, who’s gonna do it?’ ” Gannon said. “ ‘I’ve got to be able to create more offense, stick a throw in a tight window,’ and that’s where you get yourself into trouble.”

“You wouldn’t anticipate seeing this from a guy that has played as many snaps as he has played. He’s got some things in his game he’s got to clean up.”

Jaworski said the Giants’ offensive line play has led to Manning getting “cabin fever,” in which he perceives the pass rush to be in his face when in reality he has time and space to throw.

Manning’s 22 sacks are tied for 10th-fewest in the NFL, but he took 14 sacks in the Giants’ first four games.

“He got pummeled early in the season, it may have had an effect on him,” Jaworski said.

“He’s just got to keep working. He’s got incredible talent, he’s a two-time Super Bowl MVP, but sometimes it’s like a baseball batter — you’re in a slump and you have to work your way through it.”

But it’s no cinch that Manning will turn his performance around, even with the Giants riding a three-game winning streak.

Manning has been inconsistent throughout his career, but the critics have died down because of his two Super Bowl victories.

“This isn’t the first time we’ve seen this from him. He’s gone through some stretches before, and I think that’s kind of who he is,” Gannon said.

“He’s not his brother, know what I mean? Doesn’t mean he’s not a great player, but we all have our strengths and weaknesses.

“And he’s got some things he’s going to have to constantly battle through, and what it is are the two or three or four bad decisions he seems to make.”

MIGRAINE IN MIAMI

Jonathan Martin, Richie Incognito have Dolphins in tough spot

The Richie Incognito-Jonathan Martin mess in Miami is complicated, and about to get even moreso with lawyers and investigators and grievances now involved. So here is an explanation of the key issues at stake, and what’s next for all parties involved.

Martin met with investigator Ted Wells in New York City on Friday to talk about his treatment as a member of the Dolphins, and Martin will speak with owner Stephen Ross soon. Incognito filed a grievance against the Dolphins to overturn his suspension and return lost pay. And the Dolphins are bracing for an NFL investigation into the team culture and possibly a lawsuit on workplace conditions.

The NFL’s locker room culture has never been compared with normal workplace conditions in a court of law before, but the NFL has never before crossed Martin’s mother, Jane Howard-Martin, who happens to be a Harvard-educated employment lawyer and an expert in workplace harassment.

While the media coverage has focused on Martin as the target of racism and bullying, the key issue for him is whether he was justified in voluntarily leaving the Dolphins. Leaving the team without just cause means having to forfeit future game checks and returning prorated portions of his signing bonus, which was $1.9 million in 2012 after the Dolphins took him in the second round.

If the Dolphins attempt to take back Martin’s money, he could also file a grievance against the team.

But Martin may be able to keep his money if the investigation determines he was justified in leaving the team because of bullying and hazing.

Martin left the Dolphins Oct. 28, a day after the loss to the Patriots, and reportedly checked into a mental health facility for a few hours before flying home to Los Angeles.

Martin is almost certainly done with the Dolphins, and the feeling is mutual — his teammates have clearly sided against him, and Martin is tired of the poor treatment. And he could be done with the NFL — it’s hard to see Martin being accepted by another locker room after airing the Dolphins’ dirty laundry (although the Colts, with former Stanford mates Andrew Luck, Coby Fleener, and Pep Hamilton, might be able to handle him).

The key issue for Incognito, 30, is straight from “A Few Good Men”: Did Incognito “toughen up” Martin on his own, was he only following orders, or did he take it too far?

The Dolphins suspended Incognito “indefinitely” Nov. 3 for conduct detrimental to the team, but under the collective bargaining agreement they can only suspend him for four weeks without pay plus an additional week of pay.

Incognito, making $4 million this year in the final year of his contract, could lose almost $1.2 million, and he has already missed one game check.

He filed the grievance to return lost pay and be reinstated to the roster immediately, presumably under the defense that he was only carrying out orders.

Incognito filed for an expedited appeal, which per the CBA means he should have his hearing within the next week or so.

The Dolphins are bracing for an NFL investigation that could reveal some ugly truths, similar to what happened in New Orleans with Bountygate.

They are already facing a grievance from Incognito, and could face a lawsuit or similar from Martin.

No one in the building is safe, but look for Ross to find any excuse he can to keep coach JoePhilbin, who was Ross’s first signature hire.

Ross is a big fan of Philbin as a person and coach, and talked him up repeatedly in his press conference before last week’s Monday night game.

But don’t be shocked if other people in the organization take the fall for empowering Incognito to “toughen up” Martin — assistant coaches (offensive line coach Jim Turner can’t be sleeping well these days), player-relations employees, or even general manager Jeff Ireland, who is below Philbin in Ross’s pecking order.

The Dolphins’ options with Martin are limited, especially since the trade deadline has passed. They can:

■ Continue to keep him on the 53-man roster and pay him his weekly salary of $35,733.

■ Try to place him on the non-football illness list (citing Martin’s claims of mental fatigue), in which they would have the option of withholding Martin’s weekly salary until he returns.

■ Place him on the reserve/retired list, in which he could not play for the rest of 2013 and would potentially forfeit salary and signing bonus.

■ Release him, making Martin a free agent and allowing him to keep the $2.9 million he has earned in two seasons. This is obviously Martin’s preferable choice.

Assuming Incognito loses his grievance, the Dolphins have a decision to make by Dec. 2, after he has served his four-game suspension. At that point they will have to either reinstate him, or cut him and pay him the remaining balance on his salary.

Given that Incognito is set to hit free agency this offseason, it’s likely the Dolphins will end up cutting Incognito regardless of whether he wins his grievance appeal.

Incognito would then go through waivers and can be claimed or signed by any team.

ETC.

Tim Tebow could be better received in TV booth

Tim Tebow has been staying in shape and waiting for the phone to ring after getting released by the Patriots at the end of training camp, but even Tebow is realistic about his chances of ever throwing a football professionally again.

Tebow, who hasn’t had a tryout this fall despite several teams having desperate quarterback situations, reportedly is considering a career in college football broadcasting after signing well-known broadcast agent Nick Kahn of Creative Artists Agency.

Tebow’s football career is also managed by Jimmy Sexton of CAA. Tebow’s off-field endeavors, which include endorsements from Nike and Jockey, were previously managed by the William Morris Agency.

Tebow may not be a good fit for the NFL, but we think he’ll be a natural in the announcer’s booth, and that ESPN would snap him up in a second.

Stafford has a fan in Bradshaw

Many of the big-name quarterbacks around the NFL are once again having MVP-type seasons — Peyton Manning, Drew Brees, and Aaron Rodgers among them.

But when asked last Sunday on the Fox pregame show which quarterback he likes the most, Terry Bradshaw professed his love for Detroit’s Matthew Stafford. He is fourth in the NFL in passing yards (315.1 per game), has 19 touchdowns against seven interceptions, has been sacked only 10 times, and is still only 25.

“As a former quarterback, if I had to pick between Brees, [Tom]
Brady, Peyton Manning, Eli Manning,
[Ben]
Roethlisberger, and Stafford, this is the guy I’d take. I love this guy. I loved him at Georgia and I love him in Detroit,” Bradshaw said. “America, I hope the Lions are in a lot of playoff games so you’ll get to understand and see [Stafford], because he is a remarkable quarterback.”

Joe Andruzzi fund-raiser scheduled

Former Patriots offensive lineman Joe Andruzzi will be overtaking Gillette Stadium’s Putnam Club on Dec. 2 for his foundation’s sixth annual celebrity gala to raise money for cancer research.

The proceeds from The New England Celebrities Tackle Cancer Gala, which raised $500,000 last year, helps Andruzzi’s foundation provide financial assistance to cancer patients and support funding for pediatric brain cancer research at Boston Children’s Hospital.

This year’s event features a cocktail hour and silent auction, with packages including a trip to Mexico, a fighter pilot experience and a 30-minute meet-and-greet with Brady. Several current and former Patriots, as well as other Boston-area athletes, are expected to be in attendance.

Andruzzi, who won three Super Bowls with the Patriots and retired in 2006, was diagnosed with non-Hodgkin’s lymphoma in 2007 but has been cancer free since September of that year.

“Every day is a blessing,” he said last week. “Looking forward to pulling a bunch of guys out to help us raise some funds for helping these families that are going through tough times.”

Gala tickets and sponsorship packages are still available online at joeandruzzifoundation.org.

Book deal for Bill Parcells

Hall of Fame coach Bill Parcells has signed a deal with Random House’s Crown Publishing Group to write his memoir titled “Parcells: A Football Life”, co-written by sports writer Nunyo Demasio
and set for publication in the fall of 2014. “It’s been an interesting journey and I think now the time is right to look back and see what it’s all about,” Parcells said.

Quote of the week

“The more the merrier. We can go tag-team bash brothers for all I care.”

— Patriots running back Brandon Bolden, when asked about Shane Vereen returning from injured reserve and rejoining the backfield.

Ben Volin can be reached at ben.volin@globe.com. Follow him on Twitter @BenVolin. Material from interviews, wire services, other beat writers, and league and team sources was used in this report.